- The E30 is the head from Fairlady 2.0 6-cylinder motor. The Fairlady was the Japanese version of the 240Z released in 1970 in America.

- The E31 is an uncommon, desirable head that came on many 1970 240's. It's chambers were high-quench designs, however the valves were smaller than the 260 and 280 heads. Probably about 10,000 were made. After 37 years, most of them are long gone having been over-collected and used up in racing. 42cc chambers I believe. It uses an external oil spray bar.

- The E88 came on the 1971-73 240s and '74 260s, in 2 versions, small valve on the 240 and larger valve on the 260. It's chambers are the same cc size as later N42 and 47 heads. It uses an external oil spray bar.

- The larger valve N42 came on the 1975-76 280Z. 48 state U.S. 280Zs didn't use a catalytic converter until 1977, so the head came with softer brass valve seats for use with leaded gas. Many people like these for performance because of it's square exhaust ports. And as a easy mod, putting it on a flattop L28 motor puts compression in the mid 10's. It uses an external oil spray bar.

- The N47 came on the '77-80 280Z(X). It has diamond-shaped exhaust ports with emission liners, which some feel reduce flow. Starting in 1977 Nissan heads came with steel valve seats for use with unleaded gas. Like the N42, putting it on a flattop L28 motor puts compression in the mid 10's. I believe this is when Nissan changed from external oil spray bar to internal (oil holes in cam lobes)

- The P79 came on 1981-83 flattop piston L28 (F54) blocks. It has a 53.5cc chamber and must be used with flattop pistons or compression drops to 7.8:1 (with dished pistons). The exhaust ports/liners are identical to the N47, and used an internally oiled cam. It uses an internally oiled cam. See my P79 page .

- The P90 is the turbo head from the '81-82 ZX. It has the same combustion chambers as the P79, but has square exhaust ports like the N42. They both use an internally oiled cam. My P90 page.

- The P90a is an interesting turbo head which I believe came out in 1983 only. It has hydraulic valve lifters instead of standard rocker arms, which make the engine almost silent. It has identical chambers and ports to the P90 and uses an internally oiled cam. I think with a low lift, higher duration cam this head would be a hot setup. But the manuals say nothing about servicing it and replacement lifters do not exist anymore.It uses an external oil spray bar.

- Y70, E80 I've heard these heads were used on Australia/New Zealand Z's. The AU E88 was used on L28 motors. Interestingly, while the 260 was only made in 1974 in the states it was made until 1978 or so over there. I believe they had leaded 96 octane gas until the early '00s, so these may have been higher compression heads, or ones designed for leaded gas. A friend of mine has an E88 with injector ports on his L24, he suspects it received an Australian head at some point.